Use the unstable LiveKit transport type

UnstableLivekitTransport covers every shape a homeserver may advertise
while MSC4195 evolves: a LiveKit SFU `url`, a `livekit_service_url`, or
both. Switching to it means a service URL is no longer guaranteed, so the
remaining code that relies on one checks for it explicitly: delegation
probing skips transports without one, the connection map keys transports
by whichever URL they carry, and the OpenID flow rejects transports
without a service URL until the client-server API flow lands.

src/utils/test.ts

@@ -26,7 +26,7 @@ import {
 import {
   CallMembership,
   type LivekitFocusSelection,
-  type LivekitTransport,
+  type UnstableLivekitTransport,
   type MatrixRTCSession,
   MatrixRTCSessionEvent,
   type MatrixRTCSessionEventHandlerMap,
@@ -208,7 +208,7 @@ export function mockEmitter<T>(): EmitterMock<T> {
   };
 }
 
-export const exampleTransport: LivekitTransport = {
+export const exampleTransport: UnstableLivekitTransport = {
   type: "livekit",
   livekit_service_url: "https://lk.example.org",
 };